Bitbucket Server outgoing email server configuration failure

[rangarajks]

I have Bitbucket server and Jira installed on the same machine, I am using the same email server configuration for both tools, Jira works without any problem but in bitbucket, I am getting send fail with the following exception.

javax.mail.MessagingException: Could not convert socket to TLS

Email server configuration,

hostname: smtp.office365.com

Port:587

Protocol: SMTP

Use SSL/TLS if available checked

username and from address are the same

[Daniel Ebers]

Hi rangarajks,

welcome to the Atlassian Community!

The error message suggests the secured (SSL/TLS) connection to the Office 365 mailserver could not be established, most likely due to some SSL certificate issues.

In case it was not just a temporary issue with Microsoft Cloud services I'd check on a lower level first if connection works (for example using a tutorial to be found on the internet). You said you have both services running on the same machine - therefore the check should show up no problems.
The next step I would take is to check if bitbucket is utilizing the appropriate SSL certificate for Microsoft 365 service. Probably Microsoft had to renew a SSL certificate on their end.
As a last resort a clean restart of Bitbucket might also help.

Please also check if there are further errors in log file that could be of help.

Cheers,
Daniel